﻿// Upgrade NOTE: replaced '_World2Object' with 'unity_WorldToObject'

Shader "Unity Shader Book/Chapter 6/DiffuseVertexLevel"
{
    Properties
    {
        _Diffuse ("Diffuse", Color) = (1,1,1,1)
    }
    SubShader
    {
        Pass {
            Tags {"LightMode" = "ForwardBase"}

            CGPROGRAM
            //    
            #pragma vertex vert
            #pragma fragment frag
            #include "Lighting.cginc"
            
            fixed4 _Diffuse;

            struct a2v{
                float4 vertex: POSITION;
                float3 normal: NORMAL;
            };
            struct v2f{
                float4 pos: SV_POSITION;
                fixed3 color: COLOR;
            };

            v2f vert(a2v v){
                v2f o;
                o.pos = UnityObjectToClipPos (v.vertex);

                fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;

                fixed3 worldNormal = normalize(mul(v.normal, (float3x3)unity_WorldToObject));

                fixed3 worldLight = normalize (_WorldSpaceLightPos0.xyz);

                fixed3 diffuse = _LightColor0.rgb * _Diffuse.rgb * saturate (dot(worldNormal,worldLight));

                o.color = ambient + diffuse;
                
                return o;
            }

            fixed4 frag(v2f i) : SV_TARGET{
                return fixed4(i.color,1.0);
            }

            //
            ENDCG
        }
    }
    FallBack "Diffuse"
}
